Filters for cigarettes and cigars and method of manufacturing same



Oct. 31, 1961 E. I. GOLDING 3,006,346

FILTERS FOR CIGARETTES AND CIGARS AND METHOD OF MANUFACTURING SAME FiledDec. 15, 1958 Edwin I. Golding,

INVENTOR.

A T TOR/V5 Y.

nited States Patent 3,006,346 FILTERS FOR CIGARETTES AND CIGARS ANDMETHOD OF MANUFACTURING SAME Edwin I. Golding, 10573 Ashton, LosAngeles, Calif. Filed Dec. 15, 1958, Ser. No. 780,376 9 Claims. (Cl.13110) The present invention relates to novel filters for cigarettes,cigars and the like as well as to cigarettes and the like incorporatingsuch filters as a component thereof. It also relates to a method for themanufacture of such filters.

An object of the invention is to provide a filtering member which caneffectively remove a substantial proportion of the nicotine, tars andother undesirable residues produced during combustion of tobacco.

A further object of the invention is to provide a filtering member whichcan be cheaply produced in large quantities and can be handled as anindividual unit so that it can be incorporated in cigarette and cigarholders or inserted in cigarettes in place of existing filters.

An additional object of the invention is to provide a unitary filtermember which is highly eflicient and which can be readily incorporatedin a cigarette during its manufacture.

A still further object of the invention is to provide a method for themanufacture of cigarette filters of the type described which is simpleand yet efiicient and which is adapted to large volume production.

An additional object of the invention is to provide a method for theassembly of a laminated filter element incorporating a layer of granulesor particles which will retain such particles in place withoutsubstantially interfering with circulation or drawing capacity.

Filters of the type presently utilized are generally composed ofcellulosic material in the form of rolled thin paper or pads of cotton,paper or similar material. Cellular materials such as sponge, eitheralone or in combination with cotton or the like, have also been tried.Attempts have also been made to incorporate adsorptive materials in suchfilters by impregnating paper or the like with finely divided activatedcarbon and utilizing this material as a filter. Such filters have onlybeen partially successful since they remove only small proportions ofharmful ingredients, and in the case of paper impregnated with carbon,the use of any significant amount of carbon has been found to inhibitthe drawing characteristics of the cigarette while the carbon tends tobe removed from the paper and carried into the stream of smoke.Furthermore, such filters are fragile and can be handled only withdifficulty.

Applicant has discovered that an effective filter may be prepared byinterposing one or more separate layers of a particulate or granularadsorptive material such as active carbon between layers of cellularmaterial and assembling these layers in a unitary manner to form acomposite filter which can be handled as a unit without injury.Furthermore, such a filter enables the incorporation of the activematerial in a particle size which is highly effective as an adsorbentwith no danger of disintegration during use and While permitting readycirculation of smoke through the cigarette or cigar to the smoker.

The accompanying drawings and description thereof illustrate the mannerin which the invention is applied.

FIGURE 1 is a view in elevation of a cigarette incorporating one form offilter of the invention with the end tube and cigarette paper brokenaway.

FIG. 2 is a view in elevation of another form of filter made accordingto the invention.

FIG. 3 is a view in elevation of still another modified form of thefilter of the invention.

Patented Oct. 31, 1961 FIG. 4 is a view partly in elevation and partlyin cross section showing a filter of the invention introduced into acigarette holder.

FIG. 5 is a view in elevation illustrating the assembly of the filtermaterial.

FIG. 6 is a plan view illusrating the manner in which the individualfilter elements are formed.

Referring now to the drawings, 10 represents a cigarette as a whole, 11is the tobacco filling, and 12 the cigarette paper. Tubular paper endportion 13 is provided to receive the filter cylinder which is composedof a unitary laminated assembly with layers 14 and 16 or cellularmaterial and intermediate layer of active adsorbent material such asactive carbon or charcoal and bonded between the cellular layers. Thecellular layers are preferably composed of cellular sponge of the atleast partially open type. This material may be of foam rubber orviscose sponge of the conventional type or may be of sponge rubber orpolyvinyl chloride foam treated or formed to possess an interconnectedcell structure as by rolling between pressure rollers or the like as iswell known to the art. Other cellular materials permitting circulationof air therethrough may also be used. Preferably, however, applicant hasfound that cellular material of the foamed urethane type offers certainadvantages in filtering eifect, circulation of smoke, freedom from tasteand odor, and ease of fabrication and assembly. This material may be ofthe flexible, rigid, or semirigid type and is formed by methods wellknown in the art as by US. Patent Nos. 2,785,739, 2,780,606, 2,785,739,2,764,565 and others and as described in numerous publications such asModern Plastics, August 1955, pp.

102-104, 212-215, and British Plastics, January 1956, pp. 59, 39. Thesematerials have varying degrees of porosity, but even those considered asclosed cell types have a certain percentage of open cells making themporous when used in relatively thin sections. The flexible foams have agreater degree of porosity and are preferred for use in making thesefilters. In general, the cell size ranges from about 0.01 to 0.1 inch indiameter.

The adsorbent material is composed of granules or particles of an activeor activated adsorbent, a preferred example of which is active carbon oractivated charcoal. Other suitable active adsorbent materials such assilica gel or the like may also be used. Activated carbon is generallyprepared by the charring of animal matter, or by destructivedistillation of vegetable matter or by selective oxidation at relativelyhigh temperatures in the presence of water vapor in the manner wellknown in the prior art. The term active or activated carbon applies tovarious forms of carbon or charcoal which have been made active for theadsorption of gaseous and liquid materials.

The method for the manufacture of the filter element shown in FIG. 1 isillustrated in FIGS. 5 and 6. A sheet 41 of cellular material of thedesired thickness is formed. To the upper surface of this sheet isapplied a thin layer of a suitable adhesive 41a. In order to avoidexcessive blocking of the pores or cells of the material, the adhesiveis preferably applied in dilute form in a thin film. A suitablenon-blockin adhesive ha been found to be a diluted rubber latex emulsionin which the latex is diluted to about 1012 percent rubber solids. Thelatex has had incorporated therewith a small proportion of a surfaceactive agent so that when the latex is beaten or whipped a foam will begenerated. This surface active agent may be of any well-known type, suchas conventional soaps, or synthetics, such as sodium lauryl sulfate, orthe like. The foamed diluted latex is then applied to the surface of thecellular material by brushing to deposit a thin film of the adhesivematerial. Apparently the foamed adhesive permits application of the filmwithout obstructing the pores of the cellular material. At this point,while the adhesive is still tacky, a layer of granular adsorbentparticles of charcoal or the like is applied over the surface bysprinkling or dusting it on, a continuous layer being thereby anchoredto such surface, the excess being then removed. Any desired particlesize may be utilized, but a mesh size of 20-40 per inch is preferred.The thickness of the layer may also be varied but from about to about ,4of an inch is suitable with about inch being preferred, thisrepresenting a layer approximately the diameter of an average particleso that a layer one particle thick is obtained. However, a greaterthickness may be utilized as long as the layer is satisfactorilyretained between layers of cellular material. This layer issubstantially continuous and is formed by the applying of particles insuch manner that adjacent particles are in contact with each otherthroughout the layer. In this way products of combustion pass throughthe layer in contact with the particles so that tar, nicotine andsimilar impurities are adsorbed.

After the adsorbent layer is applied, a layer of adhesive 43a issimilarly applied to the under surface of the sheet of cellular material43. This sheet is then applied over the lower sheet and the layer ofadsorbent material and the layers lightly pressed together. In this waythe adsorbent particles are anchored between layers without substantialblocking of the pores of the adsorbent or the cells of the cellularmaterial. Instead of using the latex emulsion adhesive referred to,satisfactory results may be obtained by means of a highly dilutedsolvent type adhesive which is brushed or sprayed on to leave a tackysurface to which the carbon can adhere.

The composite laminated sheet is then subjected to a coring operationusing multiple cores to form individual cylindrical filter elementsillustrated in FIG. 6. As illustrated therein, a filter element havingthe structure shown in FIG. 1 is obtained. In this way a great manyfilter elements may be produced from a sheet of any desired area. Sincethe dimensions of a filter element for cigarettes are approximately 3inch in diameter and /2 to inch in length, it can be seen that a greatmany such elements can be produced cheaply per square foot of laminatedassembly.

In View of the fact that the porosity of the assembly is not appreciablyafiected by the use of the intermediate layers of adhesive andadsorbent, a plurality of separate, spaced layers of adsorbent may beutilized as illustrated in FIGS. 2 and 3. As shown in FIG. 2 filter 17is formed of layers 19 and 21 of charcoal interposed between layers 18,20 and 22 of cellular material. In FIG. 3, filter member 23 is formedwith layers 25, 27 and 29 of charcoal, bonded and spaced between layers24, 26, 28 and 30 of cellular material.

The individual filter members may be introduced into the filter tipsections of cigarettes in the conventional manner, or may be inserted inplace of existing filters in cigarettes by removing the old filter andreplacing it with one of the present type. These elements may also beutilized in cigar and cigarette holders as replaceable elements asillustrated in FIG. 4. As shown, holder 31 is formed with a tubularbarrel 32 and mouthpiece 33. A filter member of the type illustrated forexample in FIG. 2 is inserted into cavity 34. This filter is providedwith charcoal layers 36 and 38 bonded between layers 35, 37 and 39 ofcellular material, Cigarette 40 is shown in smoking position. Ifdesired, the shape of the barrel may be designed to accommodate a cigaror cheroot. A single filter has been found to remain efiective duringthe smoking of several cigarettes.

Filter elements of the type described have been found to draw well whileefiectively filtering a substantial proportion of the undesirableconstituents of tobacco smoke. In tests carried out with two well-knownpopular brands of cigarettes comparing a filter constructed according toFIG. 1 using flexible urethane foam end segments and an intermediatelayer of activated charcoal formed of particles averaging 30 mesh, thelayer being of an inch in thickness, with conventional cellulose orcharcoal impregnated paper filters as used in the cigarettes, it wasfound that the filter of this invention removed from 20 to 25 percentmore tar and from 15 to 20 percent more nicotine than the conventionalfilters. At the same time filter drawing ability was noted along withfreedom from charcoal or other particles in the effiuent smoke stream.

It will be apparent that various changes or modifications may be made inthe above-described invention, within the scope of those skilled in theart without departing from the spirit of the invention as defined in theappended claims.

I claim:

1. A filter comprising: at least two layers of porous material; and arelatively thin layer of adhesive having openings therethrough disposedbetween said layers of porous material and adapted to bond said layersof porous material together, said adhesive layer comprising adsorbent,finely divided material.

2. A filter comprising: at least first and second layers of porouscellular material; first and second relatively thin layers of adhesivehaving openings therethrough disposed upon juxtaposed surfaces of saidfirst and second layers of cellular material respectively; and a layerof adsorbent, finely divided material disposed between and bonded tosaid layers of said adhesive to thereby eifectively bond said layers ofcellular material and form a unitary filter.

3. A filter according to claim 1 wherein said adsorbent materialcomprise activated charcoal,

4. A filter according to claim 3 wherein said porous material is afoamed urethane polymer.

5. A filter according to claim- 2 wherein the cellular material is aporous, resilient sponge and the adsorbent material is activatedcharcoal.

6. A filter according to claim 5 wherein the cellular resilient materialis formed of a foamed urethane polymer.

7. A filter for use in combination with cigarettes, cigars and the likecomprising: a cylindrical assembly having a plurality of layers ofporous cellular resilient material disposed along the longitudinal axisof the cylinder; and a relatively thin layer of adhesive having openingstherethrough disposed 'between and adapted to bond together adjacentlayers of said celular material, said adhesive layer comprisingadsorbent, finely divided material.

8. A tobacco cigarette comprising a column of tobacco and a filterarranged end to end; and a Wrapper surrounding said filter and tobacco,said filter including a plurality of cylindrical segments of cellularsponge material and a continuous relatively thin layer composed ofseparate adjacent and contiguous particles of finely divided activatedcarbon disposed between said segments and adhesive material havingopenings therethrough and bonding said particles together and saidsegments to said layer and to said segments.

9. A cigarette and cigar holder which comprises a hollow cylindricalmember open at one end to receive a cigarette or cigar and communicatingat the other end with a mouthpiece, and a filter removably positioned insaid hollow member comprising: a plurality of cylindrical segments ofcellular sponge material and a continuous relatively thin layer composedof separate adjacent and contiguous particles of finely dividedactivated carbon disposed between said segments and adhesive materialhaving openings therethrough and bonding said particles together andsaid segments to said layer.

References Cited in the file of this patent UNITED STATES PATENTS288,382 Trielhoff Nov. 13, 1883 1,554,353 Johnson Sept. 22, 1925 (Otherreferences on following page) 5 UNITED STATES PATENTS Orr Feb. 28, 1939Daly Feb. 28, 1950 Stafford et a1. May 16, 1950 Brooks et a1 Mar. 3,1953 Winkler Nov. 13, 1956 6 Marek May 14, 1957 Larson May 21, 1957Hackney et a1 Sept. 10, 1957 FOREIGN PATENTS Great Britain Mar. 1, 1934

1. A FILTER COMPRISING: AT LEAST TWO LAYERS OF POROUS MATERIAL, AND ARELATIVELY THIN LAYER OF ADHESIVE HAVING OPENINGS THERETHROUGH DISPOSEDBETWEEN SAID LAYERS OF POROUS MATERIAL AND ADAPTED TO BOND SAID LAYERSOF POROUS MATERIAL TOGETHER, SAID ADHESIVE LAYER COMPRISING ADSORBENT,FINELY DIVIDED MATERIAL.